Laminated structure, display device and display unit employing same

ABSTRACT

A laminated structure which can reduce defect by preventing deposition failure or holes of an insulating film, manufacturing method, and a display unit that employ same are provided. The laminated structure as an anode for organic light-emitting devices is provided on a flat surface of a substrate. In the laminated structure, an adhesive layer made of ITO, a reflective layer made of silver or an alloy containing silver, and a barrier layer made of ITO are layered in this order from the substrate side. A cross sectional shape of the laminated structure in the laminated direction is a forward tapered shape. A sidewall face of the adhesive layer, the reflective layer, and the barrier layer is totally covered by an insulating film, and deposition failure or holes of the insulating film is prevented. A taper angle made by the sidewall face and the flat surface is preferably from about 10° to about 70°. The laminated structure can be used as a reflective electrode, a reflective film, or a wiring for a liquid crystal display.

CROSS REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/416,817, filed on Mar. 9, 2012, which is a divisional of U.S. patentapplication Ser. No. 11/549,811, filed on Oct. 16, 2006, which is acontinuation of U.S. patent Ser. No. 10/854,553, filed on May 26, 2004,which issued as U.S. Pat. No. 7,245,341 on Jul. 17, 2007, and whichclaims priority to Japanese Patent Application No. P2003-151156, filedon May 28, 2003, the disclosures of which are incorporated by referenceherein.

BACKGROUND

The present invention generally relates to a laminated structure. Morespecifically, the present invention relates to a laminated structuresuitable as a reflective electrode, a reflective film, a wiring or thelike, its manufacturing method, a display device, and a display unitthat employ same.

In recent years, as one of the flat panel displays, an organiclight-emitting display which uses organic light-emitting devices hasbeen noted. The organic light-emitting display has characteristics thatits viewing angle is wide and its power consumption is low since it is aself-luminous type display. The organic light-emitting display is alsothought of as a display having sufficient response to high-definitionand high-speed video signals, and is under development toward thepractical use.

As an organic light-emitting device, for example, a laminate wherein afirst electrode, an organic layer including a light-emitting layer, anda second electrode are sequentially layered on a substrate with a TFT(Thin Film Transistor), a planarizing layer and the like in between isknown. Light generated in the light-emitting layer may be extracted fromthe substrate side in some cases, and may be extracted from the secondelectrode side in other cases.

As an electrode on the side where light is extracted, a transparentelectrode made of a conductive material having transparency such as acompound containing indium (In), tin (Sn), and oxygen (O) (ITO: IndiumTin Oxide) is often used. Conventionally, various structures of thetransparent electrode have been proposed. For example, in order to avoidcost rise due to a thick film of ITO, a transparent electrode wherein ametal thin film made of silver (Ag) or the like and a high refractiveindex thin film made of zinc oxide (ZnO) are layered has been proposed(for example, refer to Japanese Unexamined Patent ApplicationPublication No. 2002-234792). In the transparent electrode, a thicknessof the high refractive index thin film is set to from 5 nm to 350 nm,and a thickness of the metal thin film is set to from 1 nm to 50 nm. Inthis regard, the thickness of the high refractive index thin film isrelatively thicker than the thickness of the metal thin film to raisethe transparency. In addition, reflection on the surface of the metalthin film is reduced by the high refractive index thin film.

Various metal electrodes are often used for the electrode on the sidewhere light is not extracted. For example, when light is extracted fromthe second electrode side, the first electrode as an anode is made of,for example, a metal such as chromium (Cr). Conventionally, for example,there is a suggestion that the first electrode is constructed as atwo-layer structure including a metal material layer made of chromiumand a buffer thin film layer made of an oxide including chromium, andsurface roughness of chromium making the metal material layer is reducedby the buffer thin film layer (for example, refer to Japanese UnexaminedPatent Application Publication No. 2002-216976).

When light is extracted from the second electrode side, light generatedin the light-emitting layer is directly extracted through the secondelectrode in some cases, but light generated in the light-emitting layeris once reflected by the first electrode and is emitted through thesecond electrode in other cases. Conventionally, the first electrode hasbeen made of chromium or the like. Therefore, there has been a problemthat light absorbance in the first electrode is large and loss of lightextracted after reflected by the first electrode is large. The lightabsorbance in the first electrode has a significant impact on theorganic light-emitting devices. When light-emitting efficiency is low, acurrent necessary to obtain the same intensity is increased. An increaseof the driving current significantly affects device life, which is veryimportant for practical use of the organic light-emitting devices.

Therefore, it can be thought that the first electrode is made of silver(Ag) which has the highest reflectance among metals or an alloycontaining silver. In this case, since silver is very reactive, in orderto prevent its deterioration or corrosion, providing a buffer thin filmlayer or the like on a surface of the silver layer as in the foregoingconventional art is considered to be useful.

However, when the first electrode has a laminated structure wherein thebuffer thin film layer is provided on the surface of the silver layer,there is a risk that a favorable patterning of the first electrodebecomes difficult if using the wet etching technique which isconventionally used for patterning silver. The reason thereof is thatthere is a difference between etching rates of the silver layer and thebuffer thin film layer, so that only etching in the silver layer mayrapidly proceed. When a shape of the first electrode is not good, aninsulating film covering side surfaces of the first electrode is subjectto deposition failure or holes, leading to causing defect of the organiclight-emitting devices. Dry etching technique for silver has not beendeveloped yet.

SUMMARY

The present invention generally relates to a laminated structure. Morespecifically, the present invention relates to a laminated structuresuitable as a reflective electrode, a reflective film, a wiring or thelike, its manufacturing method, a display device, and a display unitthat employ same.

The present invention provides a laminated structure which can reducedefect by preventing deposition failure and holes of an insulating film,and manufacturing method, a display device, and a display unit thatemploy same.

The laminated structure according to an embodiment of the presentinvention is provided on a surface of a substrate having a flat surface.The laminated structure is made by laminating a plurality of layers andits cross sectional shape in the laminated direction is a forwardtapered shape. A taper angle made by a sidewall face of the plurality oflayers and the flat surface of the substrate is preferably within therange of 10° to 70°. Here, the sidewall face is a sidewall face of theplurality of layers, and when a cross section of the plurality of layersis a linear flat surface, the sidewall face means the planar face.However, when its cross section is not linear such that the sidewall iscurved toward inside, that is, not flat surface, the sidewall face meansa virtual face made by a line (face) between a lower end and an upperend of the laminated structure. In an embodiment, an organic layerincluding a light-emitting layer and a second electrode are sequentiallylayered on such a laminated structure, and light generated in thelight-emitting layer is extracted from the second electrode side.Further, in an embodiment, a driving device which is electricallyconnected to a pixel electrode of a liquid crystal display device and awiring are provided on such a laminated structure. Furthermore, such alaminated structure can be a reflective electrode of the liquid crystaldisplay device in an embodiment.

A method for manufacturing the laminated structure according to anembodiment of the present invention includes sequentially laminating aplurality of layers on a flat surface of a substrate; forming a mask onthe plurality of layers; and forming a sidewall face of the plurality oflayers in a forward tapered shape by etching the plurality of layers allat once by using the mask.

A display device according to an embodiment of the present inventionincludes a laminated structure including a plurality of layers on a flatsurface of a substrate. A cross sectional shape of the laminatedstructure in the laminated direction is a forward tapered shape.

A display unit according to an embodiment of the present inventionincludes a plurality of display devices on a flat surface of asubstrate. The display device comprises a laminated structure includingplurality of layers, and a cross sectional shape of the laminatedstructure in the laminated direction is a forward tapered shape.

In the laminated structure, the display device, and the display unitaccording to an embodiment of the present invention, the cross sectionalshape in the laminated direction is a forward tapered shape. Therefore,when other film covers the laminated structure, coverage on the sidewallface is improved, and deposition failure, holes and the like areprevented.

In the method for manufacturing the laminated structure according to anembodiment of the present invention, the plurality of layers aresequentially layered on the flat surface of the substrate, and then themask is formed on the plurality of layers. Next, the sidewall face ofthe plurality of layers is formed in a forward tapered shape by etchingthe plurality of layers all at once by using the mask.

Additional features and advantages are described herein, and will beapparent from, the following Detailed Description and the figures.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a cross sectional view showing a construction of a displayunit according to a first embodiment of the present invention.

FIG. 2 is a cross sectional view showing an example of a laminatedstructure according to an embodiment of the present invention.

FIG. 3 is a cross sectional view showing another example of a laminatedstructure according to an embodiment of the present invention.

FIG. 4 is a cross sectional view showing still another example of alaminated structure shape according to an embodiment of the presentinvention.

FIG. 5 is a cross sectional view showing an enlarged construction of anorganic light-emitting device according to an embodiment of the presentinvention.

FIG. 6 is a cross sectional view showing an enlarged construction of theorganic light-emitting device according to an embodiment of the presentinvention.

FIGS. 7A and 7B are cross sectional views showing a method formanufacturing the display unit according to an embodiment of the presentinvention.

FIGS. 8A, 8B, and 8C are cross sectional views showing processesaccording to an embodiment of the present invention.

FIGS. 9A and 9B are cross sectional views showing processes according toan embodiment of the present invention.

FIG. 10 is a cross sectional view showing a process according to anembodiment of the present invention.

FIGS. 11A and 11B are cross sectional views showing processes accordingto an embodiment of the present invention.

FIG. 12 is a cross sectional view showing a process according to anembodiment of the present invention.

FIG. 13 is a cross sectional view showing a process according to anembodiment of the present invention.

FIG. 14 is a cross sectional view showing a process according to anembodiment of the present invention.

FIG. 15 is a cross sectional view showing a process according to anembodiment of the present invention.

FIG. 16 is a cross sectional view showing a process according to anembodiment of the present invention.

FIGS. 17A and 17B are cross sectional views showing processes accordingto an embodiment of the present invention.

FIG. 18 is a cross sectional view showing a process following accordingto an embodiment of the present invention.

FIG. 19 is a cross sectional view showing a construction of a displayunit according to a second embodiment of the present invention.

FIG. 20 is a cross sectional view showing a construction of a displayunit according to an embodiment of the present invention.

FIG. 21 is a cross sectional view showing a construction of a displayunit according to an embodiment of the present invention.

DETAILED DESCRIPTION

The present invention generally relates to a laminated structure. Morespecifically, the present invention relates to a laminated structuresuitable as a reflective electrode, a reflective film, a wiring or thelike, its manufacturing method, a display device, and a display unitthat employ same.

Embodiments of the present invention will be described in detailhereinbelow with reference to the drawings.

FIG. 1 shows a cross sectional structure of a display unit according toa first embodiment of the present invention. The display unit is used asan ultra-thin organic light-emitting display. A driving panel 10 and asealing panel 20 are arranged to face to each other, and their wholesurfaces are bonded together with an adhesive layer 30 made of athermosetting resin. In the driving panel 10, an organic light-emittingdevice 10R emitting red light, an organic light-emitting device 10Gemitting green light, and an organic light-emitting device 10B emittingblue light are provided in the shape of a matrix as a whole sequentiallyon a substrate 11 made of an insulating material such as glass with aTFT 12 and a planarizing layer 13 in between.

A gate electrode (not shown) of the TFT 12 is connected to an unshownscanning circuit. A source and a drain (not shown either) are connectedto a wiring 12B provided through an interlayer insulating film 12A madeof, for example, silicon oxide, PSG (Phospho-Silicate Glass) or thelike. The wiring 12B is connected to the source and the drain of the TFT12 through an unshown connecting hole provided on the interlayerinsulating film 12A to function as a signal line. The wiring 12B is madeof, for example, aluminum (Al) or an aluminum (Al)-copper (Cu) alloy.The structure of the TFT 12 is not limited particularly, and can beeither a bottom gate type or a top gate type, for example.

The purpose of a planarizing layer 13 is to planarize the surface of thesubstrate 11 wherein the TFT 12 is formed to form a flat surface 11A,and evenly form a film thickness of respective layers of the organiclight-emitting devices 10R, 10G, and 10B. In the planarizing layer 13, aconnecting hole 13A which connects a laminated structure 14 of theorganic light-emitting devices 10R, 10G, and 10B to the wiring 12B isprovided. Since the fine connecting hole 13A is formed in theplanarizing layer 13, the planarizing layer 13 is preferably made of amaterial having an excellent pattern accuracy. As a material for theplanarizing layer 13, an organic material such as polyimide, or aninorganic material such as silicon oxide (SiO₂) can be used. In thisembodiment, the planarizing layer 13 is made of an organic material suchas polyimide.

In the organic light-emitting devices 10R, 10G, and 10B, for example,from the substrate 11 side, the laminated structure (first electrode) 14as an anode, an insulating film 15, an organic layer 16 including alight-emitting layer, and a common electrode (second electrode) 17 as acathode are layered in this order with the TFT 12 and the planarizinglayer 13 in between. On the common electrode 17, a protective film 18 isformed as necessary.

The laminated structure 14 is formed on a flat surface 11A of thesubstrate 11 corresponding to the respective organic light-emittingdevices 10R, 10G, and 10B. In the laminated structure 14, a plurality oflayers are laminated. A cross sectional shape of the laminated structure14 in the laminated direction is a forward tapered shape.

The laminated structure 14 has also a function as a reflective layer. Itis desirable that the laminated structure 14 has as high reflectance aspossible in order to improve light-emitting efficiency. Therefore, thelaminated structure 14 preferably includes a reflective layer 14A madeof silver (Ag) or an alloy containing silver, because silver has thehighest reflectance among metals, and can reduce light absorbance lossin the reflective layer 14A. The reflective layer 14A that includessilver is preferable since the highest reflectance can be obtained.However, it is also preferable that the reflective layer 14A is made ofan alloy of silver and other metal, since chemical stability and processaccuracy can be improved, and adhesion between the reflective layer 14Aand an adhesive layer 14B and between the reflective layer 14A and abarrier layer 14C mentioned below can be improved. Silver is veryreactive and has low processing accuracy and adhesion, so handling isextremely difficult.

A film thickness of the reflective layer 14A in the laminated direction(hereinafter simply referred to as film thickness) is preferably fromabout 50 nm to about 200 nm, for example. When its film thickness iswithin this range, high reflectance can be obtained. Further, its filmthickness is more preferably from about 50 nm to about 150 nm. Thereason thereof is that by reducing the film thickness of the reflectivelayer 14A, its surface roughness can be reduced. Therefore, a filmthickness of the after-mentioned barrier layer 14C can be reduced toimprove light extraction efficiency. Further, by reducing the filmthickness of the reflective layer 14A, it becomes possible to reducesurface roughness of the reflective layer 14A due to crystallization ofthe reflective layer 14A by a heat process in the course ofmanufacturing, and to prevent an increase in defect of the barrier layer14C due to surface roughness of the reflective layer 14A.

It is preferable that in the laminated structure 14, the adhesive layer14B, the reflective layer 14A, and the barrier layer 14C are layered inthis order from the substrate 11 side, for example. The adhesive layer14B is provided between the flat surface 11A of the substrate 11 and thereflective layer 14A to prevent separation of the reflective layer 14Afrom the planarizing layer 13. The barrier layer 14C prevents silver oran alloy containing silver which makes the reflective layer 14A fromreacting with oxygen in the air or sulfur. The barrier layer 14C alsohas a function as a protective film to reduce damage to the reflectivelayer 14A in the manufacturing process after forming the reflectivelayer 14A. The barrier layer 14C also has a function as a surfaceplanarizing film which reduces surface roughness of the reflective layer14A made of silver or an alloy containing silver.

The barrier layer 14C is preferably made of, for example, a metalliccompound or a conductive oxide containing at least one element, such asindium (In), tin (Sn), zinc (Zn) and the like. Specifically, the barrierlayer 14C is preferably made of at least one type of material, such ascompound containing indium (In), tin (Sn) and oxygen (O) (ITO: IndiumTin Oxide); a compound containing indium (In), zinc (Zn) and oxygen (O)(IZO: Indium Zinc Oxide); indium oxide (In₂O₃), tin oxide (SnO₂), andzinc oxide (ZnO) and the like. By using these types of materials as abarrier layer 14C, planarization of the laminated structure 14 can beimproved. Therefore, film thicknesses of respective layers of theorganic layer 16 can be uniform, so that there is no danger of shortcircuit between the laminated structure 14 and the common electrode 17due to lack of film thickness of the organic layer 16. In addition,particularly when forming an after-mentioned resonator structure, colorunevenness inside pixels can be prevented and color reproducibility canbe improved. Further, since these materials have a very small lightabsorption in the visible light region, light absorption loss in thebarrier layer 14C can be reduced and light extraction efficiency can beimproved. Furthermore, the barrier layer 14C also has a function as awork function adjustment layer to raise hole injection efficiency intothe organic layer 16. Therefore, the barrier layer 14C is preferablymade of a material which has a higher work function than the reflectivelayer 14A. In view of productivity, ITO, IZO and the like areparticularly preferable in an embodiment.

In order to secure a function as the protective film mentioned above, afilm thickness of the barrier layer 14C is preferably from about 1 nm toabout 50 nm, for example. Further, in order to improve light extractionefficiency, a film thickness of the barrier layer 14C is more preferablyfrom about 3 nm to about 15 nm.

The adhesive layer 14B is preferably made of, for example, a metalliccompound or a conductive oxide containing at least one element, such asindium (In), tin (Sn), zinc (Zn) and the like. More specifically, theadhesive layer 14B is preferably made of at least one type of material,such as a compound containing indium (In), tin (Sn) and oxygen (O) (ITO:Indium Tin Oxide); a compound containing indium (In), zinc (Zn) andoxygen (O) (IZO: Indium Zinc Oxide); indium oxide (In₂O₃), tin oxide(SnO₂), and zinc oxide (ZnO). In this regard, when etching the adhesivelayer 14B after etching the barrier layer 14C and the reflective layer14A, it is not necessary to form a new mask or change an etching gas,and it is possible to conduct patterning by using the same mask and thesame etching gas.

The adhesive layer 14B preferably has a film thickness capable ofinhibiting hillock or separation of the reflective layer 14A. In anembodiment, a film thickness of the adhesive layer 14B is preferablyfrom about 5 nm to about 50 nm, and more preferably from about 10 nm toabout 30 nm.

The adhesive layer 14B and the barrier layer 14C can be made of eitherthe same material, or different materials selected from the foregoingmaterials. In an embodiment, both the adhesive layer 14B and the barrierlayer 14C are made of ITO. In an embodiment, the adhesive layer 14B ismade of ITO and the barrier layer 14C is made of IZO, respectively. Inan embodiment, both the adhesive layer 14B and the barrier layer 14C aremade of IZO. In an embodiment, the adhesive layer 14B is made of ZnO andthe barrier layer 14C is made of ITO, respectively.

The laminated structure 14 has a forward tapered shape, wherein itswidth becomes gradually narrow from the flat surface 11A of the lowerend face toward an upper end face 14D. Therefore, a sidewall face 14E ofthe adhesive layer 14B, the reflective layer 14A, and the barrier layer14C is entirely covered by the insulating film 15, and depositionfailure or holes of the insulating film 15 can be prevented.Consequently, deterioration or the like of the reflective layer 14A dueto deposition failure or holes of the insulating film 15 can beprevented, thereby avoiding defect of the organic light-emitting devices10R, 10G, and 10B.

A taper angle θ made by the sidewall face 14E of the adhesive layer 14B,the reflective layer 14A, and the barrier layer 14C and the flat surface11A of the substrate 11 is preferably within the range of about 10° toabout 70°. When the taper angle θ is smaller than about 10°, a patternof the laminated structure 14 becomes too wide, and such a condition isunfavorable for high definition. Meanwhile, when the taper angle θ ismore than about 70°, the sidewall face 14E has a precipitous propertyalmost close to perpendicularity. In this case, it is possible that theinsulating film 15 may be subject to deposition failure or holes. Thetaper angle θ is more preferably from about 25° to about 50°, and muchmore preferably from about 35° to about 45°. When the taper angle θ iswithin this range, for example, it is possible that a pattern width ΔWon one side of the laminated structure 14 can be about 0.15 μm to about0.3 μm where, for example, a total film thickness of the laminatedstructure 14 is about 130 nm. In this regard the pattern of thelaminated structure 14 is not too wide, and deposition failure and holesof the insulating film 15 can be prevented effectively.

Here, the sidewall face 14E of the adhesive layer 14B, the reflectivelayer 14A, and the barrier layer 14C means the planar face, when itscross section is linear flat surface as shown in FIG. 1. However, whenthe cross section of the sidewall face 14E is not linear, that is, notflat surface, for example, as shown in FIG. 2, the sidewall face 14E iscurved toward inside, the sidewall face 14E means a virtual face A madeby a line (face) between an end 14F of the flat surface 11A, which isthe lower end of the laminated structure 14 and an end 14G of the upperend 14D.

As shown in FIG. 3, in the sidewall face 14E of the adhesive layer 14B,the reflective layer 14A, and the barrier layer 14C, interfaces betweenthe reflective layer 14A and the barrier layer 14C, and between thereflective layer 14A and the adhesive layer 14B can be in a steppedshape due to erosion in etching. Further, as shown in FIG. 4, therespective slopes of the barrier layer 14C, the reflective layer 14A,and the adhesive layer 14B are different from each other, and a brokenline is made. It should be appreciated that the shape of the sidewallface 14E is not limited to the examples shown in FIGS. 1 to 4.

The purpose of the insulating film 15 is to secure insulation betweenthe laminated structure 14 and the common electrode 17, and to make ashape of the light-emitting region in the organic light-emitting devices10R, 10G, and 10B in a desired shape. For example, the insulating film15 has a film thickness of about 600 nm, and is made of an insulatingmaterial such as silicon oxide and polyimide. The insulating film 15 isformed to cover from the sidewall face 14E to the upper peripheral partof the laminated structure 14. An opening 15A is provided correspondingto the light-emitting region of the laminated structure 14, that is theorganic light-emitting devices 10R, 10G, and 10B.

Constructions of the organic layer 16 vary depending on colors emittedfrom the organic light-emitting devices 10R, 10G, and 10B. FIG. 5 showsan enlarged view of a construction of the organic layer 16 of theorganic light-emitting devices 10R and 10B. The organic layer 16 of theorganic light-emitting devices 10R and 10B has a construction whereinavoid transport layer 16A, a light-emitting layer 16B, and an electrontransport layer 16C are layered in this order from the laminatedstructure 14 side. The purpose of the hole transport layer 16A is toimprove efficiency of hole injection into the light-emitting layer 16B.In this embodiment, the hole transport layer 16A also has a function asan hole injection layer. The purpose of the light-emitting layer 16B isto generate recombination of electrons and holes by applying electricfield to generate light and emits light in a region corresponding to theopening 15A of the insulating film 15. The purpose of the electrontransport layer 16C is to improve efficiency of electron injection intothe light-emitting layer 16B.

The hole transport layer 16A of the organic light-emitting device 10Rhas a film thickness of about 45 nm for example, and is made of bis[(N-naphthyl)-N-phenyl] benzidine (α-NPD). The light-emitting layer 16 Bof the organic light-emitting device 10R has a film thickness of about50 nm for example, and is made of 2,5-bis[4-[N-(4-methoxyphenyl)-N-phenyl amino]] styrylbenzene-1,4-dicarbonitrile (BSB). Theelectron transport layer 16C of the organic light-emitting device 10Rhas a film thickness of about 30 nm for example, and is made of8-quinolinol aluminum complex (Alq₃).

The hole transport layer 16A of the organic light-emitting device 10Bhas a film thickness of about 30 nm for example, and is made of α-NPD.The light-emitting layer 16B of the organic light-emitting device 10Bhas a film thickness of about 30 nm for example, and is made of 4,4′-bis(2,2′-diphenyl vinyl) biphenyl (DPVBi). The electron transport layer 16Cof the organic light-emitting device 10B has a film thickness of about30 nm for example, and is made of Alq₃.

FIG. 6 shows an enlarged view of a construction of the organic layer 16of the organic light-emitting device 10G. The organic layer 16 of theorganic light-emitting device 10G has a construction wherein an holetransport layer 16A and a light-emitting layer 16B are layered in thisorder from the laminated structure 14 side. The hole transport layer 16Aalso has a function as an hole injection layer. The light-emitting layer16B also has a function as an electron transport layer.

The hole transport layer 16A of the organic light-emitting device 10Ghas a film thickness of about 50 nm for example, and is made of α-NPD.The light-emitting layer 16B of the organic light-emitting device 10Ghas a film thickness of about 60 nm for example, and is made of Alq₃mixed with 1 vol % of Coumarin 6 (C6).

The common electrode 17 shown in FIGS. 1, 5, and 6 has a film thicknessof about 10 nm for example, and is made of a metal or an alloy of silver(Ag), aluminum (Al), magnesium (Mg), calcium (Ca), sodium (Na) or thelike. In this embodiment, for example, the common electrode 17 is madeof an alloy of magnesium (Mg) and silver (MgAg alloy).

The common electrode 17 is formed to cover all the organiclight-emitting devices 10R, 10G, and 10B. In order to inhibit voltagedrop in the common electrode 17, it is preferable that an auxiliaryelectrode 17A is provided on the insulating film 15. The auxiliaryelectrode 17A is provided in gaps between the organic light-emittingdevices 10R, 10G, and 10B. An end of the auxiliary electrode 17A isconnected to a trunk-shaped auxiliary electrode (not shown) whichbecomes a bus for the auxiliary electrode 17A, which is formed in aperipheral part of the substrate 11 to surround the area where theorganic light-emitting devices 10R, 10G, and 10B are provided. Theauxiliary electrode 17A and the trunk-shaped auxiliary electrode of thebus are made of a monolayer of a low-resistance conductive material suchas aluminum (Al) and chromium (Cr), or a laminated structure thereof.

The common electrode 17 also has a function as a semi-transparentreflective layer. That is, the organic light-emitting devices 10R, 10G,and 10B have a resonator structure, wherein light generated in thelight-emitting layer 16B is resonated and extracted from a second end P2side by using the organic layer 16 and the barrier layer 14C as aresonant part, where an interface between the reflective layer 14A andthe barrier layer 14C of the laminated structure 14 is a first end P1,and an interface of the common electrode 17 on a side close to thelight-emitting layer 16B is the second end P2. When the organiclight-emitting devices 10R, 10G, and 10B have such a resonatorstructure, light generated in the light-emitting layer 16B generatesmultiple interference and acts as a kind of a narrow-band filter. Inresult, a half value width of the spectrum of extracted light isreduced, and color purity can be improved. Therefore, such a resonatorstructure is preferable. This resonator structure is preferable, sinceoutside light entering from the sealing panel 20 can be attenuated bymultiple interference, and a reflectance of outside light can besignificantly reduced in the organic light-emitting devices 10R, 10G,and 10B by combining with an after-mentioned color filter 22 (refer toFIG. 1).

In order to obtain the foregoing effects, it is preferable that anoptical distance L between the first end P1 and the second end P2 of theresonator satisfies Mathematical Formula 1, and a resonant wavelength ofthe resonator (peak wavelength of the spectrum of light to be extracted)and a peak wavelength of the spectrum of the light desired to beextracted correspond to each other. Actually, the optical distance L ispreferably selected to be a positive minimum value to satisfyMathematical Formula 1 as follows:(2L)/λ+Φ/(2π)=m

In the formula, L represents an optical distance between the first endP1 and the second end P2; Φ represents the sum of a phase shift Φ₁ ofthe reflected light generated in the first end P1 and a phase shift Φ₂of the reflected light generated in the first end P2 (Φ=Φ₁+Φ₂) (rad); λrepresents a peak wavelength of a spectrum of light desired to beextracted from the second end P2 side; and m represents an integernumber which gives a positive value of L. In Mathematical Formula 1,units for L and λ should be common, that is, nm is used as a unit forthem, for example.

The protective film 18 shown in FIG. 1 has a film thickness of about 500nm to about 10,000 nm for example, and is a passivation film made of atransparent dielectric. The protective film 18 is made of, for example,silicon oxide (SiO₂), silicon nitride (SiN) or the like.

As shown in FIG. 1, the sealing panel 20 is positioned on the commonelectrode 17 side of the driving panel 10. The sealing panel 20 includesa sealing substrate 21 which seals the organic light-emitting devices10R, 10G, and 10B along with the adhesive layer 30. The sealingsubstrate 21 is made of a material transparent to light generated in theorganic light-emitting devices 10R, 10G, and 10B such as glass. Thesealing substrate 21 includes the color filter 22 for example. The colorfilter 22 extracts light generated in the organic light-emitting devices10R, 10G, and 10B, absorbs outside light reflected in the organiclight-emitting devices 10R, 10G, and 10B, and the wiring therebetween,thereby the contrast is improved.

The color filter 22 can be provided on either side of the sealingsubstrate 21. However, it is preferable to provide the color filter 22on the driving panel 10 side, since the color filter 22 is not exposedon the surface, and can be protected by the adhesive layer 30. The colorfilter 22 comprises a red filter 22R, a green filter 22G, and a bluefilter 22B, which are sequentially arranged corresponding to the organiclight-emitting devices 10R, 10G, and 10B, respectively.

The red filter 22R, the green filter 22G, and the blue filter 22B areformed in a rectangular shape with no space in between. The red filter22R, the green filter 22G, and the blue filter 22B are made of a resinmixed with pigments, respectively. By selecting the pigments, adjustmentis made so that the light transmittance in a target wavelength of red,green, or blue can be high, and the light transmittance in otherwavelengths can be low.

A wavelength range having a high transmittance in the color filter 22corresponds to a peak wavelength λ of a spectrum of light to beextracted from the resonator structure. Therefore, among outside lightentering from the sealing panel 20, only the light which has awavelength equal to a peak wavelength λ of a spectrum of light to beextracted passes through the color filter 22, and outside light havingother wavelength is prohibited from entering the organic light-emittingdevices 10R, 10G, and 10B.

This display unit can be manufactured as follows, for example.

FIGS. 7A to 18 show the steps in a method for manufacturing the displayunit in order. First, as shown in FIG. 7A, the TFT 12, the interlayerinsulating film 12A, and the wiring 12B are formed on the substrate 11made of the foregoing materials.

Next, as shown in FIG. 7B, the planarizing layer 13 made of theforegoing material is formed over the whole area of the substrate 11 byspin coat method, for example, the planarizing layer 13 is patterned ina given shape by exposure and development, and the connecting hole 13Ais formed. After that, in order to transform polyimide into imide, theresultant is baked in a clean baking furnace at, for example, about 320°C.

Subsequently, as shown in FIG. 8A, the adhesive layer 14B made of, forexample, ITO having a film thickness of, for example, about 20 nm isformed on the flat surface 11A formed by the planarizing layer 13 bysputtering for example.

After that, as shown in FIG. 8B, the reflective layer 14A made of, forexample, an alloy containing silver having a film thickness of, forexample, about 100 nm is formed on the adhesive layer 14B by, forexample, sputtering. By forming the reflective layer 14A on theplanarizing layer 13 with the adhesive layer 14B in between as above, itbecomes possible to prevent the reflective layer 14A from beingseparated from the planarizing layer 13 as a base layer. Further, itbecomes possible to prevent intrusion of an etching solution, air or thelike from the separated portion, and to prevent silver or an alloycontaining silver making the reflective layer 14A from reacting withoxygen or sulfur contained in the etching solution or the air.

Next, as shown in FIG. 8C, the barrier layer 14C made of, for example,ITO having a film thickness of, for example, about 10 nm is formed onthe reflective layer 14A by, for example, sputtering. By forming thebarrier layer 14C immediately after forming the reflective layer 14A, itbecomes possible to prevent silver or an alloy containing silver makingthe reflective layer 14A from reacting with oxygen or sulfur in the air.Further, it becomes possible to reduce damage to the reflective layer14A even in the manufacturing process after forming the reflective layer14A, and maintain the interface between the reflective layer 14A and thebarrier layer 14C clean.

After forming the adhesive layer 14B, the reflective layer 14A, and thebarrier layer 14C, as shown in FIG. 9A, a mask 41 made of, for example,a photoresist film is formed on the barrier layer 14C by using, forexample, lithography.

Subsequently, as shown in FIG. 9B, by using the mask 41, the barrierlayer 14C, the reflective layer 14A, and the adhesive layer 14B areetched all at once. The sidewall face 14E is thereby formed in a forwardtapered shape. Here, as mentioned above, a taper angle θ made by thesidewall face 14E and the flat surface 11A of the substrate 11 ispreferably within the range of about 10° to about 70°.

This etching performed all at once needs to be provided by dry etching.If using wet etching, the barrier layer 14C, the reflective layer 14A,and the adhesive layer 14B cannot be patterned all at once, and a newmask needs to be formed at least once in the middle of etching whenetching the adhesive layer 14B, for example. Therefore, considering roomof mask alignment and the like it cannot be avoided that a flat surfaceis formed at the interface between the reflective layer 14A and theadhesive layer 14B, so that it is difficult to form the sidewall face14E in a forward tapered shape. Further, when using the wet etching,there is a large difference, twice or more between etching rates of ITOand silver, for example. Therefore, only silver might be rapidly etchedand side etching might proceed unless their etching rates are totallythe same. Meanwhile, when using the dry etching, even if there is adifference between etching rates of ITO and silver, problems such asside etching never arise though slightly uneven shape is obtained asshown in FIGS. 2 to 4. In result, in the dry etching, the sidewall face14E can be formed in a forward tapered shape.

In the dry etching, it is preferable to use an etching gas containing acomponent capable of forming a volatile compound with all the reflectivelayer 14A, the adhesive layer 14B, and the barrier layer 14C. Morespecifically, for example, an etching gas containing methane (CH₄) ispreferably used. Methane reacts with silver to produce methyl silver(AgCH₃). This methyl silver is volatile, and is easy to be removed. Whenthe adhesive layer 14B and the barrier layer 14C are made of, forexample, a material containing indium (In), methane reacts with indium(In) to produce methyl indium (In (CH₃)₃). This methyl indium is alsovolatile, and is easy to be removed. Meanwhile, for example, when usingan etching gas containing a component which forms an involatile compoundwith silver, such as halogen, for example, fluoride (F), chlorine (Cl),this involatile reaction product is deposited on the sidewall face 14E,and removal of such a deposited product is difficult. Therefore, usingsuch an etching gas is not preferable.

Regarding control of etching conditions to form the sidewall face 14E ina forward tapered shape, various methods can be thought. For example,there is a method as follows. By using an unshown plasma light-emittingmonitor, exposure of the surface of the adhesive layer 14B afterfinishing etching of the barrier layer 14C and the reflective layer 14Ais detected. After that, etching conditions are changed. That is, asshown in FIG. 10, etching conditions are changed as follows. Along withetching progress of the adhesive layer 14B, a deposition protective film42 is formed on the exposed sidewall face 14E of the barrier layer 14Cand the reflective layer 14A. This deposition protective film 42 isformed by depositing an organic substance derived from methane or thelike on the sidewall face 14E of the barrier layer 14C and thereflective layer 14A. Due to the deposition protective film 42, theadhesive layer 14B can be etched while protecting the sidewall face 14Ewhich is already formed in a forward tapered shape.

There is other method as follows. After detecting exposure of thesurface of the adhesive layer 14B, etching conditions are changed asfollows. That is, for example, by raising an etching rate of ITO, anetching selection ratio of the adhesive layer 14B and the planarizinglayer 13 on the substrate 11 is improved.

Further, it is possible to adopt etching conditions to satisfy theforegoing two methods. That is, it is possible to adopt the conditionswherein the deposition protective film 42 is formed, and an etchingselection ratio of the adhesive layer 14B and the planarizing layer 13on the substrate 11 is improved as well.

As concrete etching conditions after change, the following techniquescan be utilized, for example. For example, a technique to promotedeposition of the deposition protective film 42 by increasing methaneflow rate, a technique to modify a vertical component of the etching gasby changing pressure from the high vacuum side to low vacuum side, and atechnique to modify a vertical component of the etching gas by loweringbias power can be utilized.

In this embodiment, for example, when forming the laminated structure 14having the taper angle θ of about 30°, etching conditions before changeis set to as follows: a flow rate of methane is 20 SCCM, a flow rate ofargon (Ar) is 20 SCCM, a pressure is 1.5 Pa, a bias power is 1,000 W.Meanwhile, etching conditions after change is set to as follows: a flowrate of methane is 40 SCCM, a flow rate of argon is 20 SCCM, a pressureis 3 Pa, a bias power is 750 W. This is a case on the assumption thatthe sidewall face 14E is formed in a forward tapered shape while formingthe deposition protective film 42.

After that, as shown in FIG. 11A, the mask 41 is removed. Then, as shownin FIG. 11B, the insulating film 15 having the foregoing film thicknessis deposited over the whole area of the substrate 11 by, for example,CVD (Chemical Vapor Deposition). After that, the opening 15A is formedby selectively removing a part of the insulating film 15 correspondingto the light-emitting region by using, for example, lithography.

Next, as shown in FIG. 12, the auxiliary electrode 17A is formed on theinsulating film 15 over the whole area of the substrate 11. Then, theauxiliary electrode 17A is selectively etched and patterned in a givenshape by using, for example, lithography.

Subsequently, as shown in FIG. 13, the electron transport layer 16A, thelight-emitting layer 16B, and the electron transport layer 16C of theorganic light-emitting device 10R, which respectively have the foregoingfilm thickness and are made of the foregoing materials, are sequentiallydeposited to form the organic layer 16 of the organic light-emittingdevice 10R by, for example, deposition. In this regard, it is preferablethat deposition is performed corresponding to the light-emitting region,that is, the opening 15A of the insulating film 15 by using a metaldeposition mask 51 having an opening 51A corresponding to the regionwhere the organic layer 16 is formed. However, it is difficult toprecisely deposit the organic layer 16 only in the opening 15A.Therefore, deposition may be performed to cover the whole opening 15A,and the organic layer 16 may slightly cover edges of the insulating film15.

After that, the deposition mask 51 is shifted. Then, as shown in FIG.14, in a manner similar to in the organic layer 16 of the organiclight-emitting device 10R, the hole transport layer 16A and thelight-emitting layer 16B of the organic light-emitting device 10G, whichhave the foregoing film thickness and are made of the foregoingmaterials are sequentially deposited to form the organic layer 16 of theorganic light-emitting device 10G. Subsequently, the deposition mask 51is shifted again. Then, also as in FIG. 14, in a manner similar to inthe organic layer 16 of the organic light-emitting device 10R, the holetransport layer 16A, the light-emitting layer 16B, and the electrontransport layer 16C of the organic light-emitting device 10B, which havethe foregoing film thickness and are made of the foregoing materials aresequentially deposited to form the organic layer 16 of the organiclight-emitting device 10B. FIG. 14 shows a condition, wherein theopening 51A of the deposition mask 51 is facing to the organic layer 16of the organic light-emitting device 10B.

After forming the organic layer 16 of the organic light-emitting devices10R, 10G, and 10B, as shown in FIG. 15, the common electrode 17 whichhas the foregoing film thickness and is made of the foregoing materialis formed over the whole area of the substrate 11 by, for example,deposition. The common electrode 17 is thereby electrically connected tothe auxiliary electrode 17A and the unshown trunk-shaped auxiliaryelectrode which becomes a bus, which are already formed before.Consequently, the organic light-emitting devices 10R, 10G, and 10B shownin FIGS. 1, 5, and 6 are thereby formed.

Next, as shown in FIG. 16, the protective film 18 which has theforegoing film thickness and is made of the foregoing material is formedon the common electrode 17. Thereby, the driving panel 10 shown in FIG.1 is formed.

As shown in FIG. 17A, for example, the red filter 22R is formed bycoating a material for the red filter 22R on the sealing substrate 21made of the foregoing material by, for example, spin coat, patterningthrough photolithography, and firing the resultant. Subsequently, asshown in FIG. 17B, as in a manner similar to in the red filter 22R, theblue filter 22B and the green filter 22G are sequentially formed. Thesealing panel 20 is thereby formed.

After forming the sealing panel 20 and the driving panel 10, as shown inFIG. 18, the adhesive layer 30 made of a thermosetting resin is formedby coating on a side of the substrate 11 wherein the organiclight-emitting devices 10R, 10G, and 10B are formed. The coating can beperformed by, for example, discharging a resin from a slit nozzle typedispenser, roll coating, or screen printing. Next, as shown in FIG. 1,the driving panel 10 and the sealing panel 20 are bonded together withthe adhesive layer 30 in between. In this regard, it is preferable thata side of the sealing panel 20 where the color filter 22 is formed isarranged facing to the driving panel 10. It is preferable to avoid airbubbles and so on from entering into the adhesive layer 30. After that,relative positions of the color filter 22 of the sealing panel 20 andthe organic light-emitting devices 10R, 10G, and 10B of the drivingpanel 10 are aligned. Then, the thermosetting resin of the adhesivelayer 30 is cured by performing heat treatment at a given temperaturefor a given time. The display unit shown in FIGS. 1, 5, and 6 is therebycompleted.

In this display unit, for example, when a given voltage is appliedbetween the laminated structure 14 and the common electrode 17, currentis injected into the light-emitting layer 16B of the organic layer 16,and holes and electrons are recombined. In result, light emitting arisesmainly on the interface of the light-emitting layer 16B on the holetransport layer 16A side. This light multiple-reflects between the firstend P1 and the second end P2, passes through the common electrode 17,and is extracted. Here, a cross section of the laminated structure 14 inthe laminated direction is a forward tapered shape. Therefore, thesidewall face 14E is favorably covered with the insulating film 15.Consequently, deterioration of the reflective layer 14A due todeposition failure or holes of the insulating film 15 is prevented, anddefect of the organic light-emitting devices 10R, 10G, and 10B isreduced.

As above, in this embodiment, a cross section of the laminated structure14 in the laminated direction is a forward tapered shape. Therefore,deposition failure or holes of the insulating film 15 can be prevented,deterioration of the reflective layer 14A can be surely prevented, anddefect of the organic light-emitting devices 10R, 10G, and 10B can bereduced. Consequently, this embodiment is particularly suitable for thecase wherein the laminated structure 14 includes the reflective layer14A made of silver (Ag) or an alloy containing silver. In this case, areflectance of the laminated structure 14 can be improved, and lightextraction efficiency can be improved.

In this embodiment, after all the adhesive layer 14B, the reflectivelayer 14A, and the barrier layer 14C are formed on the flat surface 11Aof the substrate 11, they are etched all at once. Therefore, thesidewall face 14E can be easily formed in the forward tapered shape asmentioned above.

FIG. 19 shows a cross sectional structure of a display unit according toa second embodiment of the invention. This display unit is used as atransmissive/reflective (semi-transmissive) liquid crystal display. Inthis display unit, a driving panel 60 and an opposing panel 70 arearranged to face to each other, and a liquid crystal layer 80 isprovided between them.

In the driving panel 60, a pixel electrode 62 is provided in the shapeof a matrix on a substrate 61 made of, for example, glass. On thesubstrate 61, an active driving circuit including a TFT 63 as a drivingdevice electrically connected to the pixel electrode 62, a wiring 63Aand the like is formed. On the side of the substrate 61 facing to theliquid crystal layer 80, an alignment film 64 is provided over the wholearea, and on the opposite side of the substrate 61, a polarizing plate65 is provided. A laminated structure 14 similar to the laminatedstructure in the first embodiment is provided between the surface of thesubstrate 61, and the TFT 63 and the wiring 63A. For example, aninsulating film 66 is provided between the laminated structure 14, andthe TFT 63 and the wiring 63A.

The pixel electrode 62 includes a transparent electrode 62A and areflective electrode 62B, for example. The transparent electrode 62A ismade of, for example, ITO, and the reflective electrode 62B is made of,for example, aluminum (Al), silver (Ag) or the like. The reflectiveelectrode 62B is formed to lie on part of the transparent electrode 62A.A region wherein the reflective electrode 62B lies on the transparentelectrode 62A is a reflective display region, and a region wherein thereflective electrode 62B does not lie on the transparent electrode 62Ais a transmissive display region.

A gate electrode (not shown) of the TFT 63 is connected to an unshownscanning circuit. A source (not shown) is connected to the wiring 63A asa signal line. A drain (not shown) is connected to the pixel electrode62. A material for the wiring 63A is the same for the wiring 13B in thefirst embodiment. A construction of the TFT 63 is not particularlylimited as in the TFT 12 in the first embodiment. The TFT 63 and thewiring 63A are covered with a protective film 63B made of, for example,silicon oxide (SiO₂) silicon nitride (SiN) or the like.

In this embodiment, the laminated structure 14 has a role as areflective film to reflect incident light which did not enter thetransparent electrode 62A and return such a light to an unshownbacklight side. A material and a film thickness of the adhesive layer14B, the reflective layer 14A, and the barrier layer 14C, a shape of thesidewall face 14E, a range of a taper angle θ made by the sidewall face14E and a flat surface 61A of the substrate 61 and the like are similarto those of the first embodiment.

The alignment film 64 is made of, for example, an oblique depositionfilm such as silicon oxide (SiO₂). In this case, an after-mentionedpretilt angle of the liquid crystal layer 80 is controlled by changing adeposition angle in oblique deposition. As the alignment film 64, a filmobtained by providing an organic compound such as polyimide with rubbing(alignment) treatment can be used. In this case, a pretilt angle can becontrolled by changing rubbing conditions.

The polarizing plate 65 is an optical device which changes light fromthe unshown backlight into linear polarized light in a certaindirection. For example, the polarizing plate 65 includes a polyvinylalcohol (PVA) film and the like.

The insulating film 66 is made of, for example, silicon oxide (SiO₂) orthe like. As the insulating film 66, a polyimide film can be useddepending on processes.

The opposing panel 70 is positioned on the pixel electrode 62 side ofthe driving panel 60 and comprises an opposite substrate 71 made ofglass or the like. On the opposite substrate 71, for example, atransparent electrode 72 and a color filter 73 are sequentially layeredfrom the opposite substrate 71 side, facing to the pixel electrode 62.Further, on the opposite substrate 71, a light absorbing film 74 as ablack matrix is provided along the interface with the color filter 73.On the side of the opposite substrate 71 facing to the liquid crystallayer 80, an alignment film 75 is provided over the whole area, and onthe opposite side, a polarizing plate 76 is provided.

The transparent electrode 72 is made of, for example, ITO or the like.The color filter 73 is constructed as in the color filter 22 in thefirst embodiment. The light absorbing film 74 is intended to absorboutside light entering the opposite substrate 71 or reflected light ofthe outside light reflected by the wiring 64 to improve contrast. Forexample, the light absorbing film 74 is made of a black resin filmwherein black coloring is mixed, which has an optical density of 1 ormore, or a thin film filter utilizing interference of a thin film. Thethin film filter is made by layering one or more thin films made of ametal, a metal nitride, or a metal oxide. The thin film filterattenuates light by utilizing interference of thin films. As the thinfilm filter, a filter wherein chromium and chromium oxide (III) (Cr₂O₃)are alternately layered can be cited specifically. The alignment film 75and the polarizing plate 76 are constructed as in the alignment film 64and the polarizing plate 65 of the driving panel 60.

The liquid crystal layer 80 changes a transmittance by changingalignment conditions due to voltage application. If dip directions ofliquid crystal molecules are uneven in driving, the contrast becomesuneven. In order to avoid uneven contrast, a slight pretilt angle ispreviously given to the liquid crystal layer 80 in a certain direction.

This display unit can be manufactured as follows, for example.

First, the laminated structure 14 whose sidewall face 14E is in aforward tapered shape is formed on a flat surface 61A of the substrate61 by firstly layering all the adhesive layer 14B, the reflective layer14A, and the barrier layer 14C and then etching them all at once as in amanner similar to in the first embodiment. Next, the insulating film 66made of the foregoing material is formed by, for example, CVD to coverthe laminated structure 14. Further, the transparent electrode 62A andthe reflective electrode 62B are formed to form the pixel electrode 62.Subsequently, the TFT 63 and the wiring 63A are formed on the laminatedstructure 14 and the insulating film 66, and then the protective film63B is formed by, for example, CVD. After that, the alignment film 64 isformed over the whole area of the substrate 61, and rubbing treatment isprovided. The driving panel 60 is thereby completed.

The transparent electrode 72, the light absorbing film 74, and the colorfilter 73 are formed on the surface of the opposite substrate 71. Next,the alignment film 75 is formed on the whole area of the oppositesubstrate 71, and rubbing treatment is provided. The opposing panel 70is thereby formed.

Next, for example, a seal material (not shown) made of, for example, anepoxy resin is provided in the periphery part of the driving panel 60 orthe opposing panel 70, and a spherical or columnar spacer (not shown) isprovided. Subsequently, the driving panel 60 and the opposing panel 70are aligned so that the pixel electrode 62 and the transparent electrode72 face to each other, and are bonded together by curing the sealmaterial. Then, the liquid crystal layer 80 is injected inside, and theresultant is sealed. After that, the polarizing plate 65 is attached tothe driving panel 60, and the polarizing plate 76 is attached to theopposing panel 70. The display unit shown in FIG. 19 is therebycompleted.

In this display unit, for example, when a given voltage is appliedbetween the pixel electrode 62 and the transparent electrode 72,alignment conditions of the liquid crystal layer 80 are changed, and atransmittance is changed. Incident light R1 entering the transparentelectrode 62A from the unshown backlight passes through the liquidcrystal layer 80, and is extracted as a transmitted light R2. Incidentlight R3 entering the reflective electrode 62B or the laminatedstructure 14 from the backlight is reflected by the reflective electrode62B or the reflective layer 14A of the laminated structure 14, and itsreflected light R4 returns to the backlight side. The reflected light R4enters the pixel electrode 62 again by an unshown reflecting mirrorprovided on the backlight. Further, an outside light H1 entering fromthe opposing panel 70 side is reflected by the reflective electrode 62B,and its reflected light H2 is extracted. Here, a cross section of thelaminated structure 14 in the laminated direction is formed in a forwardtapered shape. Therefore, the sidewall face 14E is favorably covered bythe insulating film 66, the alignment film 64 or the like. Therefore,deterioration or the like of the reflective layer 14A due to depositionfailure or holes of the insulating film 66, the alignment film 64 or thelike can be prevented.

As above, in this embodiment, as in the first embodiment, the crosssection of the laminated structure 14 in the laminated direction isformed in a forward tapered shape. Therefore, deposition failure orholes of the insulating film 66, the alignment film 64 or the like canbe prevented, and deterioration or corrosion of the reflective layer 14Acan be surely prevented. Therefore, this embodiment is particularlysuitable for the case where the laminated structure 14 includes thereflective layer 14A made of silver (Ag) or an alloy containing silver.In this case, it is possible to raise a reflectance of the laminatedstructure 14 to improve utilization efficiency of the backlight, and toreduce power consumption of the display unit.

While the invention has been described with reference to theembodiments, the invention is not limited to the foregoing embodiments,and various modifications may be made. For example, the materials,thicknesses, depositions, deposition conditions and the like are notlimited to those described in the foregoing embodiments. Othermaterials, thicknesses, depositions, and deposition conditions can beapplied.

For example, in the foregoing embodiments, descriptions have been givenof the case wherein the adhesive layer 14B and the barrier layer 14C aremade of a metal compound or a conductive oxide containing at least oneelement, such as indium (In), tin (Sn), zinc (Zn) and the like,particularly of the case wherein the adhesive layer 14B and the barrierlayer 14C are made of at least one type of material, such as ITO, IZO,indium oxide (In₂O₃), tin oxide (SnO₂), zinc oxide (ZnO) and the like.However, one of the adhesive layer 14B and the barrier layer 14C can bemade of a material other than the foregoing materials. For example, forthe barrier layer 14C, its material is not limited to the foregoingmaterials as long as a material is transparent, has a small lightabsorbance, and is capable of being etched with the reflective layer 14Aand the adhesive layer 14B all at once.

Further, for example, for the adhesive layer 14B, deposition, CVD, MOCVD(Metal Organic Chemical Vapor Deposition), laser ablation, and platingcan be used in addition to sputtering. Similarly, for the reflectivelayer 14A, deposition, CVD, MOCVD, laser ablation, and plating can beused in addition to sputtering.

In addition, in the foregoing first embodiment, descriptions have beengiven of the construction of the organic light-emitting devices 10R,10G, and 10B with a concrete example. However, it is no need to provideall the layers such as the insulating film 15, the auxiliary electrode17A, the protective film 18 and the like, and other layer can be furtheradded. This invention can be applied also to the case wherein the commonelectrode 17 is not a semi-transparent electrode but a transparentelectrode, and has no resonator structure. However, this invention isintended to raise a reflectance in the laminated structure 14.Therefore, when the resonator structure is constructed by setting theorganic layer 16 and the barrier layer 14C to a resonant part, where theinterface between the reflective layer 14A and the barrier layer 14C ofthe laminated structure 14 is the first end P1, and the interface of thecommon electrode 17 on the light-emitting layer 16B side is the secondend P2, higher effects can be obtained.

Further, in the second embodiment, descriptions have been given of thetransmissive/reflective liquid crystal display as an example. However,this invention can be applied to other types of the liquid crystaldisplays. For example, as shown in FIG. 20, it is possible to providethe laminated structure 14 as a reflective film in a transmissive liquidcrystal display. As shown in FIG. 21, it is also possible that thelaminated structure 14 is used as a reflective pixel electrode. It isalso possible that the laminated structure 14 is provided instead of thereflective electrode 62B or the wiring 63A in the second embodiment.

In addition, in the foregoing second embodiment, descriptions have beengiven of the construction of the liquid crystal display device with aconcrete example. However, it is no need to provide all the layers ormembers. Further, additional other layers or other members can be added.

Further, in the foregoing embodiments, descriptions have been given ofthe case wherein the invention is applied to the display units such asthe organic light-emitting display unit and the liquid crystal displayunit. However, application of the laminated structure of the inventionis not limited to application as a reflective electrode or a reflectivefilm. For example, the laminated structure of the invention can be usedas a metal wiring by taking advantage of low resistance in thereflective layer 14A. In this case, the metal wiring capable ofpreventing silver corrosion, and having a superior performance can berealized.

In addition, application of the display device, particularly the organiclight-emitting device of the invention is not always limited to thedisplay unit. For example, a simple lighting not intended for displaycan be made according to an embodiment.

As described above, according to the laminated structure, the displaydevice, and the display unit of the invention, the cross section of thelaminated structure in the laminated direction is formed in a forwardtapered shape. Therefore, coverage in the sidewall face is improved, anddeposition failure or holes of the insulating film or the like coveringthe sidewall face can be prevented.

According to the method for manufacturing the laminated structure of theinvention, the sidewall face is formed in a forward tapered shape byfirstly forming all the plurality of layers on the surface of thesubstrate, and then etching them all at once. Therefore, the laminatedstructure in the forward tapered shape can be easily formed.

It should be understood that various changes and modifications to thepresently preferred embodiments described herein will be apparent tothose skilled in the art. Such changes and modifications can be madewithout departing from the spirit and scope of the present subjectmatter and without diminishing its intended advantages. It is thereforeintended that such changes and modifications be covered by the appendedclaims.

The invention claimed is:
 1. A display device comprising: a firstelectrode; a second electrode; and an organic layer arranged between thefirst electrode and the second electrode, wherein the first electrodehas a laminated structure including a reflective layer, and thelaminated structure has a tapered shape in cross section.
 2. The displaydevice according to claim 1, wherein the organic light-emitting deviceincludes a hole transport layer.
 3. The display device according toclaim 1, wherein the organic light-emitting device includes an electrontransport layer.
 4. The display device according to claim 1, wherein theorganic layer includes an organic light-emitting device configured toemit red light.
 5. The display device according to claim 4, wherein theorganic light-emitting device includes a light-emitting layer having athickness of about 50 nm.
 6. The display device according to claim 4,wherein the organic light-emitting device includes a hole transportlayer having a thickness of about 45 nm.
 7. The display device accordingto claim 4, wherein the organic light-emitting device includes anelectron transport layer having a thickness of about 30 nm.
 8. Thedisplay device according to claim 1, wherein the organic layer includesan organic light-emitting device configured to emit green light.
 9. Thedisplay device according to claim 8, wherein the organic light-emittingdevice includes a light-emitting layer having a thickness of about 60nm.
 10. The display device according to claim 8, wherein the organiclight-emitting device includes a hole transport layer having a thicknessof about 50 nm.
 11. The display device according to claim 1, wherein theorganic layer includes an organic light-emitting device configured toemit blue light.
 12. The display device according to claim 11, whereinthe organic light-emitting device includes a light-emitting layer havinga thickness of about 30 nm.
 13. The display device according to claim11, wherein the organic light-emitting device includes a hole transportlayer having a thickness of about 30 nm.
 14. The display deviceaccording to claim 11, wherein the organic light-emitting deviceincludes an electron transport layer having a thickness of about 30 nm.15. The display device according to claim 1, wherein the organic layerincludes an organic light-emitting device configured to emit red light,an organic light-emitting device configured to emit green light and anorganic light-emitting device configured to emit blue light.
 16. Thedisplay device according to claim 1, wherein the laminated structurefurther includes a barrier layer attached to the organic layer.
 17. Thedisplay device according to claim 16, wherein the barrier layer isthinner than the reflective layer.
 18. The display device according toclaim 16, wherein the barrier layer is thinner than the organic layer.